Almost a year after a devastating earthquake and tsunami crippled Japan’s Fukushima Daiichi nuclear complex, there’s an emerging consensus in Japan and Germany that the hazards of nuclear energy overshadow its benefits. In the United States and other countries, the question remains unresolved.

In Nuclear Aftershocks, airing Tuesday, January 17, 2012, at 10 P.M. ET on PBS (check local listings), FRONTLINE correspondent Miles O’Brien travels to three continents to explore the revived debate about the safety of nuclear power, the options for alternative energy sources, and questions about whether a disaster like the one at Fukushima could happen in the United States.

The Fukushima accident marked a nuclear tipping point. Only six of Japan’s 54 reactors are still operating, and all are expected to be closed by May 2012. For its part, Germany decided to close all of its 17 reactors by 2022, with hopes of filling the power gap with renewable energy sources like wind and solar. But some climatologists are concerned that Japan and Germany’s carbon-free nuclear electricity will be replaced not with renewables but with polluting fossil fuels like coal. As NASA’s James Hansen says, “It’s really extremely bad timing. … We have not yet found a base-load electric power without carbon emissions, other than nuclear power.”

FRONTLINE examines the implications of the Fukushima event for U.S. nuclear safety and asks if any of our 104 reactors could suffer a Fukushima-type accident. According to Nuclear Regulatory Commission (NRC) chairman Gregory Jaczko, “The likelihood of a Fukushima accident happening here is very low, … but we know it’s not impossible.” But David Lochbaum, the chief nuclear expert for the Union of Concerned Scientists, argues that the NRC’s record is far from perfect. “The biggest concern I’ve had with the NRC over the years I’ve been monitoring them is lack of consistency. They’re a little bit slow at solving known safety problems.” For example, Lochbaum says, 47 reactors in the U.S. still do not meet federal fire protection standards — standards that were set 35 years ago, after a fire at the Browns Ferry nuclear plant in Alabama.

O’Brien examines one of the most controversial decisions facing U.S. nuclear regulators: whether to relicense the nearly 40-year-old Indian Point nuclear plant, located 38 miles from Manhattan. Citing the damage to Fukushima Daiichi’s 40-year-old reactors, critics — including New York Gov. Andrew Cuomo — insist that the risks are too great. But proponents, among them former New York City Mayor Rudolph Giuliani, argue that keeping Indian Point open is essential, as it provides about a quarter of New York City and Westchester County’s carbon-free electricity.

In the relatively sparsely populated area near the Japanese plant, the radiation caused major disruptions. According to radiation biologist John Moulder, “Some of the [contaminated] areas outside the plant in Fukushima Daiichi … are not going to be re-inhabitable anytime in [the residents’] lifetime.” An Indian Point accident, in a much more densely populated area, would pose even greater challenges in evacuating residents and cleaning up after any release of radiation.

Nuclear Aftershocks is a FRONTLINE production with Palfreman Film Group. The producer and director is Jon Palfreman. The correspondent is Miles O’Brien. The writers are Miles O’Brien and Jon Palfreman. The co-producer is Kate McMahon. FRONTLINE is produced by WGBH Boston and is broadcast nationwide on PBS. Funding for FRONTLINE is provided through the support of PBS viewers and by the Corporation for Public Broadcasting. Major funding for FRONTLINE is provided by The John D. and Catherine T. MacArthur Foundation and by Reva and David Logan. Additional funding is provided by the Park Foundation and the FRONTLINE Journalism Fund. Major funding for Nuclear Aftershocks is provided by the Alfred P. Sloan Foundation. FRONTLINE is closed-captioned for deaf and hard-of-hearing viewers and described for people who are blind or visually impaired by the Media Access Group at WGBH. FRONTLINE is a registered trademark of WGBH Educational Foundation.

PHOTO CREDIT: PBS photo of Indian Point Nuclear Energy Plant in Beacon, NY.